Building material



June 9, 1931. F, PAYNE BUILDING MATERIAL Filed May 28, 1928 Patented June 9, 1931 UNITED STATES PATENT OFFICE FRANK PAYNE, OF CHICAGO, ILLINOIS, ASSIGNOB TO WESTERN BRICK COMPANY, OF DANVILLE, ILLINOIS, A CORPORATION OF ILLINOIS BUILDING MATERIAL Application filed Kay 28,

This invention relates to a new. and improved artificial stone and method of making the same, and more particularly to an artificial stone havin acoustical properties and therefore especial y adapted for use in auditoriums or the like.

'It has been found that one of the main sources of poor acoustical properties of auditoriums and other rooms used for similar purposes lies in the fact that the sounds are reflected and reverberated from the wall surfaces of the room. The usual surfaces of such rooms are of solid laster or concrete and are ordinarily finis ed with a hard, smooth and dense surface. It has been found by experiment that such surfaces reflect the sound and by repeated reflections cause sound confusion and materially reduce the acoustical properties of the room.

It is an object of the present invention to provide a material especially adapted for use upon the surface of auditoriums or the like.

It is a further object to provide a material of this character and method of makin the same whereby the'surface of the material is largely porous.

It is a further object to provide a material of this character whichis of architectural beauty in addition to its acoustical properties.

It is also an ob'ect to provide a material and method of making the same whereby the material may be produced at low cost in commercial quantities.

Other and further objects will appear as the description proceeds.

I have illustrated in the accompanying drawing one preferred embodiment of m invention. The single figure of the drawing represents a slab of the material.

In the drawing the pieces of material 11 are bonded by cementitious material 12. It will be noted that the pieces of material 11 present a porous surface and that they constitute the major portion of the exposed surface of the material. Y

My improved material may be made up from a. wide variety of materials such as blast furnace slag, cinders, coke, burned shale or burned clay and other similar materials. The

1928. Serial No. 281,196.

essential feature of thematerials is that they must be capable of being sawed or split or otherwise readily divided to present a smooth but porous surface. It will be understood that by porous is meant a surface which is not absolutely hard and dense but it is not es sential that. the surface present large cells. The porosity may be such a character as to be readily apparent to the naked eye or it may have a finer porosity such as is not readily visible.

The binding material used to hold the aggregatetogether may be a Portland or gypsum cement or a limp cement, or the binder may be asphaltic or bituminous in character. In the production of my improved material the aggregate and binding material are thoroughly, mixed and placed in proper forms until the material has hardened for use. It is then essential, however, that the material be either split or sawed or otherwise cut to expose cut surfaces of the aggregate. It will -be apparent that if the block were simply used as cast the greater proportion of the surface would consist of the binding material with only small points of aggregate exposed through the surface of the material since the aggregate is irregular in form. By sawing or splitting the cast block a surface is obtained'in which the major portion of the area .consists of the aggregate used. This surface may be obtained by grinding awa or polishing the surface of the cast block sufficiently to thus expose the aggregate rather than by sawing or splitting it.

While "I have described a number of materials suitable for use as aggregate and a y number of binding materials which have been found suitable .in the preferred form of my invention, I use burned clay or shale commercially known as Haydite and the binding material is preferably Portland cement. The burned clay or shale may be secured in a wide variety of colors and the binder may also be colored, if desired. It is, therefore, possible to provide a material in' desired color combinations which is not only very satisfactory due to these sound absorbing qualities, but is of also great architectural beauty.

While the material has been described as particularly valuable for use in auditoriums or the like, it is also desirable for use in interior finish, such as wainscoting or wall board or wherever the properties of sound deadening are desirable. While I have shown and described one particular form of my invention, it is capable of variation to meet different conditions and purposes, and I contemplate such changes and modifica tions as come within the spirit and scope of the appended claims.

I claim:

1. Building material having acoustical properties comprising burned shale bonded together with cement, the surface of the material being smooth and exposing smooth, out surfaces of the burned shale.

2. Building material having acoustical properties comprising burned shale bonded together with cement, the surface of the material being smooth and exposing smooth, cut surfaces of the burned shale, said shale surfaces constituting the major portion of the total surface of the material.

Signed at Chicago, Illinois, this 19th day FRANK PAYNE.

of May, 1928. 

